Chest /respiratory X Rays Flashcards
Skeletal anatomy of chest
(7)
Ribs
Spine
Vertebrae
Scapulae
Clavicles
Sternum
Proximal humerus
Cartilaginous structures of chest cavity
Xiphoid process or xiphisternum
Costal cartilage
Respiratory anatomy of the chest
Lungs
Airway s
Diaphragm
Digestive anatomy of chest
Oesophagus
Circulatory
Heart
Major blood vessels - arterial or venous
What is the difference between the lobes in the right and left lung
Right lung has 3 lobes
Left lung has 2 lobes to make room for the heart as the hearts apex is tilted to the left which makes the left lung smaller than the right
Fissures
Lines on the lungs
2 on right and 1 on left
Right horizontal fissure
Right oblique fissure
Left oblique fissure
What do we take chest x rays for
Clinical indications
-lung disease
-infections
-tumours
Cardiac assessments
Airway assessments
Bony assessments
Standard projections of CXR
PA
AP
Non standard projections for CXR
Lateral
Oblique - usually for fractured ribs
How to do a PA chest x-ray
X ray tube and beam behind patient
Patients chest touching detector to reduce magnification of chest cavity
Why PA CXR view
-gold standard CXR so no annotation required unless an alternative projection like an AP used
-improves image quality and is sharper
-Reduces magnification of the heart
-less dose on the thyroid gland since its radio sensitive
When the object is _____________ to the detector it is ________________ and _______________.
When the object is closer to the detector it is smaller and sharper on the image
Positioning for PA CXR
-patient stood up straight
-chest close to detector (touching)
-medial saggital plane is perpendicular and at right angles to detector
-shoulders shrugged forwards which moved scapula out of lung field
-dorsum of hands on hips
-elbows partially flexed and forwards
-head and neck straight and forward
-tell patient to breathe in but leave shoulders relaxed which shows apex
-expose patient at deepest breath in but remember to tell them to breathe again
How to assess a CXR
10 point checklist (PAC ACC DAAR)
1.patient ID- 3 forms of ID
2. Area of interest- thorax
3. Correct protection - PA no annotation required
4.Anatomical markers- Left marker electronically placed
5.collimation- shoulders to the 12th rib / costal margins
6.correct exposure- lung markings, vertebra visible behind heart shadow
7.definition/sharpness - clear and sharp, costophrenic and cardiophrenic angles visible, diaphragm clearly outlines
8.artefacts- none visible
9.any pathology- nothing obvious
10. Any need for a repeat- NO
Assessing a CXR for a good patient position
-medial ends of clavicles needs to be equidistant so same length away from vertebrae
-scapula needs to be out of lung fields
-vertebrae needs to be seen behind the heart shadow
If the lung fields looks fuzzy what does the patient have to do…
Chest infection
Cardiothoracic ratio (PA CXR only)
Ratio of the greatest transverse dimension of the heart to the greatest transverse dimension of the chest cavity
0.42-0.5 ratio is normal
Detects enlargement of the heart if above 50% of the chest cavity
Which is known as cardiomegaly
Further cardiac investigations are normally needed for a higher ratio
Cardiomegaly
An enlarged heart on a PA CXR
Normal = cardiothoracic ratio is less than 0.5/ 50%
Can have pacemakers
When do you take an Anterior posterior CXR and what is the positioning ?
-When PA is not possible
-patient neeeds to be sat upright or supine and as straight as possible
-medial saggital plates at right angles to the detector
-patients back against the detector
-x ray beam from the front
-scapula as lateral as possible to keep out of lung field (shrug forwards)
-chin up (look up)
-practice a breathe in and holding
-x ray Beam perpendicular to the detector
AP CXR image assessment
10 point checklist
PAC AAC DAAR
Can do AP in supine position in ITU or the resuscitation room but ensure its annotated as supine so report can be accurate
Erect (upright) in standard anatomical position
SID for erect and supine
SID- Erect 180cm
SID- supine 100cm
Detector side for AP or PA
43 x 53cm (large)
Centering point for PA and AP
PA- T7 vertebra (bottom of scapula aligns with T7)
AP- mid sternum (15-25 degree caudal angle)
BOTH PERPENDICULAR TO DETECTOR
